The term “sand shark” refers to the Sand Tiger Shark, Carcharias taurus, a species found in coastal waters worldwide. While other sharks may inhabit sandy areas, the Sand Tiger Shark is most commonly known by this name.
Identifying Sand Sharks
Sand Tiger Sharks have a distinctive appearance. They have a stout, bulky body, reaching lengths of up to 10.5 feet (3.2 meters) and weighing around 350 pounds (159 kg), with females growing larger than males. Their coloration is light brown to grayish above, fading to a paler underside. Many individuals, especially juveniles, display darker reddish-brown spots scattered across their backs and sides, which fade as they mature.
They have a pointed, flattened snout and a mouth that extends behind their small eyes. Even when their mouth is closed, several rows of long, narrow, needle-like teeth protrude. These non-serrated teeth are designed for piercing and holding prey. They have two dorsal fins that are equal in size and broad-based, with the first dorsal fin positioned further back on the body. Their caudal fin is asymmetrical, featuring a pronounced upper lobe.
Life in Their Habitat
Sand Tiger Sharks inhabit subtropical and temperate waters globally, excluding the eastern Pacific. They are found along continental shelves in shallow coastal waters, including surf zones, bays, estuaries, and around reefs, but can also be found at depths up to 627 feet (191 meters). These sharks are observed swimming slowly near the bottom or hovering motionlessly. They undertake seasonal migrations, moving poleward in summer and towards the equator in fall and winter.
Their diet consists of bony fish such as herring, bluefish, and eels, but they also consume small sharks, skates, crustaceans, and squid. Sand Tiger Sharks are nocturnal hunters, using specialized electroreceptors to detect prey, particularly those hidden in the sand. They hunt cooperatively in groups, surrounding and bunching schools of fish before feeding. A unique behavior is gulping air from the surface and storing it in their stomach. This allows them to achieve neutral buoyancy, hovering motionless with minimal effort, which assists in stealthy hunting.
The reproductive strategy of Sand Tiger Sharks is distinct among sharks. They are ovoviviparous, meaning eggs hatch inside the mother’s uteri. Females give birth to only one or two large pups every two to three years, a low reproductive rate for sharks. This low number is due to intrauterine cannibalism, where the most developed embryo in each uterus consumes other eggs and less developed embryos, ensuring the surviving pups are large and well-developed at birth.
Interactions with Humans
Despite their intimidating appearance and visible teeth, Sand Tiger Sharks are not aggressive towards humans. Bites on humans are rare and occur when the shark is provoked, such as during spearfishing or harassment. As of 2023, the International Shark Attack File lists 36 unprovoked, non-fatal attacks attributed to Sand Tiger Sharks, with no confirmed human fatalities. Their teeth are suited for grasping small, slippery prey rather than inflicting severe damage on larger animals.
The global population of Sand Tiger Sharks is assessed as Critically Endangered by the International Union for Conservation of Nature (IUCN). This status is due to significant population reductions, estimated to be more than 80% over the past 74 years, largely driven by overfishing and habitat degradation. Their slow reproductive rate makes them vulnerable to population decline and hinders recovery efforts.
Sand Tiger Sharks are sought after in commercial and recreational fisheries for their meat, fins, liver oil, and hides. They are also susceptible to accidental capture in fishing gear. Due to their docile nature and distinctive appearance, Sand Tiger Sharks are popular exhibits in public aquariums, offering opportunities for safe viewing and education.